Human serum cholinesterase: Variations during pregnancy and post-partum

Forty-seven patients demonstrating prolonged apnoea after suxamethonium have been investigated in a 3-year survey carried out in southeast Scotland. Clinical information, and serum cholinesterase studies using a new substrate, succinyldithiocholine, provide evidence on the aetiology of suxamethonium hypersensitivity. While 13 patients possessed only variant forms of the serum enzyme, the remaining 34 patients appeared to have a catalytically active form of cholinesterase. The causes of prolonged apnoea in the latter group are discussed. The value of screening the relatives of patients with cholinesterase variants is demonstrated by the finding of 26 relatives "at risk" out of 123 screened.

Section: Family Studiesmentioning

confidence: 99%

Aetiology of Prolonged Apnoea After Suxamethonium

Bauld¹,

Gibson²,

Jebson³

et al. 1974

“…This may reflect the greater cardiac output of full-term pregnant women. The duration of blockade was also significantly longer in the pregnant women and this may be caused by reduced pseudocholinesterase activity (Hazel and Monier, 1971).…”

Section: Discussionmentioning

confidence: 97%

Emergency Intubation of the Trachea Facilitated by Suxamethonium

Carnie¹,

Street²,

Kumar³

1986

The relationship between the time of onset of neuromuscular blockade and the time at which laryngoscopy was attempted was studied in patients presenting for emergency obstetric or emergency general surgical procedures. "Train-of-four" stimulation and visual observation of the evoked twitch response in the hand were used as a measure of the degree of neuromuscular blockade. The attendant anaesthetist was unaware of the response to the peripheral nerve stimulator. Intubation preceded complete neuromuscular blockade; in the obstetric patients there was no correlation between the two times. The use of a peripheral nerve stimulator should allow the anaesthetist to perform intubation in emergency situations with a greater degree of safety.

“…Although the changes in cholinesterase activity throughout the 40 weeks of gestation have been studied widely (Piccoli and Longo, 1947;Levine and Hoyte, 1949;Shnider, 1965;Robertson, 1966;Hazel and Monier, 1971;Evans and Wroe, 1980), at present little precise information is available which defines the pattern of recovery of cholinesterase activity post-partum. It is, however, accepted universally that the decrease in enzyme activity continues for several days postpartum (Shnider, 1965;Hazel and Monier, 1971;Blitt et al, 1977;Evans and Wroe, 1980) before returning to normal non-pregnant values between the 10th day (Piccoli and Longo, 1947) and the 6th week post-partum (Barnes and Epperson, 1952), although the latter is probably an over-generous estimate of the time required to restore the cholinesterase activity to its non-pregnant value. Successive pregnancies have no repercussions on cholinesterase activities, thus indicating that antibody formation does not result in decreased cholinesterase activity (Hazel and Monier, 1971).…”

Section: Discussionmentioning

confidence: 99%

“…It is, however, accepted universally that the decrease in enzyme activity continues for several days postpartum (Shnider, 1965;Hazel and Monier, 1971;Blitt et al, 1977;Evans and Wroe, 1980) before returning to normal non-pregnant values between the 10th day (Piccoli and Longo, 1947) and the 6th week post-partum (Barnes and Epperson, 1952), although the latter is probably an over-generous estimate of the time required to restore the cholinesterase activity to its non-pregnant value. Successive pregnancies have no repercussions on cholinesterase activities, thus indicating that antibody formation does not result in decreased cholinesterase activity (Hazel and Monier, 1971). Despite the decrease in the value of cholinesterase activity at the time of Caesarean section the patient exhibited no evidence of "suxamethonium sensitivity".…”

Section: Discussionmentioning

confidence: 99%

Postoperative Ileus, Pregnancy-Related Cholinesterase Deficiency and Suxamethonium After-Pains

Whíttaker

Crawford

1983

An account is presented of a patient who developed ileus, of greater or lesser severity, after each of seven operations (including two extra-abdominal and three Caesarean sections). During her most recent pregnancy, reviewed here, her plasma cholinesterase activity was found to be decreased and it remained low until at least the 6th day post-partum. However, as the normal activity had been gained by 6 weeks after delivery, the phenomenon had evidently been pregnancy-related. Despite receiving suxamethonium by infusion to completion of her Caesarean section, she did not show an abnormally prolonged response, although she did suffer considerable suxamethonium "after-pains". The question is posed of a possible relationship between the postoperative ileus, muscle pains and the decrease in cholinesterase activity.